NEB_Initial_Path Failed 2

[Yannis Lazarou]

Dear NWchemists,

For Diels-Alder reaction systems, the minimum energy path optimization by the Nudged Elastic Band (NEB) method fails at its very beginning, with the error message:
neb_initial_path failed  2

A few more lines surrounding the error message:
 ....
 neb: NEW NEB CHAIN, INITIALIZING
 ------------------------------------------------------------------------
 neb_initial_path failed                   2
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
  current input line :
   112: TASK DFT NEB IGNORE
 ------------------------------------------------------------------------
 ------------------------------------------------------------------------
 This error has not yet been assigned to a category
 ------------------------------------------------------------------------
 ....

I have tweaked several input file parameters with no effect whatsoever. What am I still missing?
The NWChem version is 7.0.2
The contents of a typical input file are appended at the end of this message.

Thank you very much!

Yannis G. Lazarou



ECHO
MEMORY 12000 MB
TITLE "rp-endo-DA"
START rp-endo-DA_wrk

permanent_dir .
scratch_dir .

GEOMETRY NOCENTER NOAUTOSYM NOAUTOZ
 C     0.50389975      0.33865154     -1.32398200
 C     0.09640432      0.55246508     -2.78877831
 C    -1.30612099      1.07499862     -3.11990499
 C    -2.33946896      0.49807072     -2.13174081
 C    -1.94993091      0.68755877     -0.66952074
 C    -0.65720069     -0.07240617     -0.38702464
 H     1.55027699      0.33554447     -0.95142853
 C     1.01457810      0.36549342     -3.74559021
 H    -1.31763017      2.11551809     -3.05180216
 H    -1.55822825      0.80848682     -4.11471796
 H    -3.31356096      0.96242130     -2.33765626
 H    -2.44517064     -0.57875359     -2.32886362
 H    -1.84765625      1.75519383     -0.43406653
 H    -2.74473667      0.30648160     -0.01738393
 H    -0.32745981      0.09118366      0.64886701
 H    -0.86868554     -1.13829982     -0.49515641
 C     1.86588252     -0.86180604     -3.95379972
 H     1.17643714      1.14335775     -4.48881435
 H     1.98195195     -1.68914413     -3.23553824
 H     2.66164279     -1.00717878     -4.69533539
 C     3.56149626     -2.56290078      0.31486726
 C     5.05635834     -2.27151895      0.04800582
 C     6.22443295     -3.24952936      0.11814559
 C     5.77319193     -4.64924574      0.17760718
 C     4.47053719     -5.06024456      0.25506413
 C     3.35362983     -4.08935308      0.35744834
 H     6.99584007     -3.15886402      1.04171252
 H     2.66673899     -4.28219414     -0.61694717
 H     6.93827200     -3.08283997     -0.84534949
 H     2.61637926     -4.38190699      1.17638624
 H     6.40993977     -5.27682018      0.05874693
 H     4.12318611     -6.01345348      0.22979116
 H     2.78962398     -1.89320278      0.26717436
 H     5.43723965     -1.33015203      0.45240963
END

GEOMETRY ENDGEOM NOCENTER NOAUTOSYM NOAUTOZ
 C     2.31216168     -4.06417274     -1.26763558
 C     2.67944145     -3.79464531     -2.73378110
 C     3.85455966     -4.54262781     -3.37369490
 C     4.98395634     -4.74629831     -2.34406924
 C     4.50608921     -5.36987543     -1.03701091
 C     3.51184940     -4.43017149     -0.36104918
 H     1.57858336     -4.89747906     -1.23481953
 C     1.91022372     -2.97012424     -3.45611715
 H     3.44348049     -5.46704388     -3.79104328
 H     4.27307129     -3.95820379     -4.25358963
 H     5.76712847     -5.36316681     -2.80539322
 H     5.43166876     -3.76671696     -2.12113595
 H     4.06329679     -6.35762596     -1.22157705
 H     5.35849428     -5.53826714     -0.36820626
 H     3.11299539     -4.88111401      0.55878854
 H     4.05336571     -3.52743244     -0.07081771
 C     0.71352911     -2.19211578     -2.96911168
 H     2.15408492     -2.79159570     -4.50113535
 H     0.93249398     -1.11922848     -3.09134459
 H    -0.15601663     -2.38593864     -3.60982561
 C     1.62634718     -2.79861760     -0.70818019
 C     0.33699971     -2.48076940     -1.50034964
 C    -0.46298531     -1.30589211     -0.94749498
 C     0.40607080     -0.25274110     -0.39812291
 C     1.76843131     -0.32220840     -0.29429007
 C     2.51641583     -1.54339385     -0.68110371
 H    -1.06387961     -1.79066825     -0.02015960
 H     2.92135692     -1.37644506     -1.80652845
 H    -1.33887160     -0.83151937     -1.53275156
 H     3.47187138     -1.74318647     -0.05464983
 H    -0.06232032      0.55875540     -0.13488638
 H     2.34882379      0.35556412      0.06274366
 H     1.35091126     -2.98655224      0.34301090
 H    -0.33545944     -3.34121275     -1.45434892
END

BASIS
 * Library 6-31G*
END

DFT
 XC M06-2X
 SYM ON
 ADAPT ON
 DIRECT
 GRID MEDIUM
 GRID NODISK
 ITERATIONS 512
 CGMIN
 MULT 1
END

NEB
 NBEADS 10
 KBEADS 0.1
 MAXITER 100
 STEPSIZE 1.0
 PRINT_SHIFT 1
END

TASK DFT NEB IGNORE

[Edoardo Aprà]

The "endgeom" geometry label is case sensitive. In other words, only lower case "endgeom" works.

Here is how the the second geometry entry should start

GEOMETRY endgeom NOCENTER NOAUTOSYM NOAUTOZ
 C     2.31216168     -4.06417274     -1.26763558

I strongly recommend you to use lower case characters in NWChem input files to avoid bugs like this one.

[Yannis Lazarou]

Thanks a lot, Edoardo!

These specific case requirements may be always a nuissance but I guess there are good reasons justifying their existence. Sorry for having bothered you with trivial matters. I will always try to follow your suggestion.

Best regards,

Yannis

--
You received this message because you are subscribed to a topic in the Google Groups "NWChem Forum" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/nwchem-forum/x3H6JSvaeck/unsubscribe.
To unsubscribe from this group and all its topics, send an email to nwchem-forum...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/nwchem-forum/d46a0b90-b527-4d5a-90e1-4df2633d3a3dn%40googlegroups.com.